Ingredient Guide•Onion
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Good source of PotassiumSource of FiberLow Calorie
VegetablesAlliumsCentral Asia
OnionCalories, Nutrition Facts, Culinary Uses & Recipes
Scientific Name:Allium cepa
Also known as:
PyazKanda
Onions are foundational cooking vegetables. Contain quercetin, a powerful antioxidant. Support immune and heart health. Aid digestion and gut balance.
Calories (100g)40 kcal
Dietary ProfileVegan & Vegetarian
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Calories in Onion & Nutritional Facts
Standard food-composition values per 100g edible portion and realistic serving portions
How many calories are in Onion?
100 grams of Onion (raw/dry reference weight) provides approximately 40 kcal, 10.3g carbohydrates, 1.2g protein, 0.1g fat, and 1.7g dietary fiber. A realistic single-person portion of 50g contains roughly 20 kcal before cooking oils or garnishes.
40.0kcal
Calories
1.2g
Protein
10.3g
Carbs
0.1g
Fat
1.7g
Fiber
4.2g
Sugar
| Portion Size | Calories | Carbs | Protein | Fat | Fiber |
|---|---|---|---|---|---|
| Per 30g (Small / 2–3 Tbsp) | 12 kcal | 3.1g | 0.4g | 0.0g | 0.5g |
| Per 50g (Standard Home Serving) | 20 kcal | 5.2g | 0.6g | 0.1g | 0.8g |
| Per 100g (Standard Reference) | 40 kcal | 10.3g | 1.2g | 0.1g | 1.7g |
Source & Disclaimer: Nutritional figures represent approximate values per 100g edible portion compiled from standard food-composition references (including ICMR-NIN Indian Food Composition Tables & USDA FoodData Central). Values vary by grain thickness, moisture, brand, and added cooking oils or garnishes. Provided for general culinary information only and not as medical or clinical dietary advice.
Storage Instructions
Keep Onion fresh and long-lasting
Room Temperature Shelf Life: Fresh onions last up to 4 weeks at room temperature without refrigeration when kept in a cool, dark, and well-ventilated space. Pantry vs Refrigerator: Avoid storing them in plastic bags or inside the refrigerator, as excess humidity causes mold and sprouting; keep them in traditional wire baskets or porous jute bags away from potatoes. Long-Term Freezing: For extended storage, chop or slice the onions and freeze them raw in airtight containers or silicone bags for up to 3 months.
Kitchen Preparation & Cooking Uses
Best culinary practices & prep tips
Which Variety to Choose: Select red onions for raw salads and quick pickling, yellow onions for rich, long-simmered Indian gravies, and white onions for mild chutneys and clear broths. Bloom in Healthy Fats: Finely dice onions and sauté them slowly in ghee or mustard oil until deeply caramelized to build the robust flavor base for curries and biryanis. Slice Against the Grain: For even softening during tadka and quick stir-fries, slice onions perpendicular to the root-to-stem axis.
General Nutritional & Wellness Notes
Everyday dietary context for Onion as part of balanced home cooking
Onions are nutrient-dense root vegetables packed with essential vitamins, minerals, and bioactive plant compounds that promote overall wellness. They are rich in dietary fiber and prebiotic fructans, which support healthy digestion and gut microbiome balance, while their high concentration of quercetin and sulfur compounds helps combat oxidative stress and supports heart health.
Culinary Uses, Origins & Cultural Heritage
How Onion is used across regional kitchens and history
Common Culinary Uses
Historically valued not just as food but as currency and medicine, ancient Egyptians worshipped onions for their spherical shape symbolizing eternity, and placed them in the tombs of pharaohs.
Historical Roots
Onions are native to Central Asia and have been cultivated by human civilizations for over 5,000 years, spreading early through ancient trade routes to the Middle East, Egypt, and the Indian subcontinent.
Regional & Cultural Traditions
In traditional Indian kitchens, onions serve as the quintessential foundational ingredient alongside garlic and ginger, forming the aromatic 'bhuna' base for countless regional curries, dals, and sabzis. Globally, they are celebrated as one of the indispensable holy trinities of world cuisine, anchoring French mirepoix, Spanish sofrito, and Italian soffritto.
Did You Know?
Did you know that crying while cutting onions is caused by a chemical irritant gas released when the onion's cell walls are ruptured, which can be prevented by chilling the onion beforehand to slow down the enzymatic reaction?
Chef & Cooking Tips
If your onion-based gravy tastes overly sharp or bitter, balance the harshness by stirring in a spoonful of yogurt, fresh cream, or a touch of jaggery to mellow the pungent notes.
Recipes Using Onion
Explore 9 recipes featuring Onion
Frequently Asked Questions about Onion
Common questions on calories, cooking methods, and kitchen storage
How many calories are in Onion?
Per 100 grams (raw/dry reference weight), Onion contains approximately 40 kcal, 10.3g carbohydrates, 1.2g protein, 0.1g fat, and 1.7g dietary fiber. A typical 50g culinary portion provides roughly 20 kcal before cooking oils, butter, or garnishes are added.
What is Onion and how is it used in cooking?
Onions are foundational cooking vegetables. Contain quercetin, a powerful antioxidant. Support immune and heart health. Aid digestion and gut balance.
How do you prepare and cook with Onion?
Which Variety to Choose: Select red onions for raw salads and quick pickling, yellow onions for rich, long-simmered Indian gravies, and white onions for mild chutneys and clear broths. Bloom in Healthy Fats: Finely dice onions and sauté them slowly in ghee or mustard oil until deeply caramelized to build the robust flavor base for curries and biryanis. Slice Against the Grain: For even softening during tadka and quick stir-fries, slice onions perpendicular to the root-to-stem axis.
How should Onion be stored to keep it fresh?
Room Temperature Shelf Life: Fresh onions last up to 4 weeks at room temperature without refrigeration when kept in a cool, dark, and well-ventilated space. Pantry vs Refrigerator: Avoid storing them in plastic bags or inside the refrigerator, as excess humidity causes mold and sprouting; keep them in traditional wire baskets or porous jute bags away from potatoes. Long-Term Freezing: For extended storage, chop or slice the onions and freeze them raw in airtight containers or silicone bags for up to 3 months.
What are the nutritional qualities of Onion?
Onions are nutrient-dense root vegetables packed with essential vitamins, minerals, and bioactive plant compounds that promote overall wellness. They are rich in dietary fiber and prebiotic fructans, which support healthy digestion and gut microbiome balance, while their high concentration of quercetin and sulfur compounds helps combat oxidative stress and supports heart health. (For general culinary reference only, not medical advice.)
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